On 16 October 2011 08:51, Stephen Tetley <stephen.tet...@gmail.com> wrote: > On 15 October 2011 23:56, Bas van Dijk <v.dijk....@gmail.com> wrote: >> On 15 October 2011 23:17, Ertugrul Soeylemez <e...@ertes.de> wrote: >>> Both instances are valid here, and there is no mechanism to choose one of >>> them. >> >> There is: OverlappingInstances[1] chooses the most specific instance. >> So in case someVector :: Vector Word8 the instance Show (Vector Word8) >> is chosen because it's the most specific. > > This has the problem of incoherence in multi-module programs - GHC > might chose different instances for the same type depending on > compilation order. For a Show instance, this may be acceptable.
But is this a problem when both instances are exported from the same module and OverlappingInstances is only enabled in that module, as is the case here? _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
